It was Kazakhstan. In the fifties was tried to cultivate the land of it and Brezhnev wrote a book "Celina" about it.
Russisa
Iran
Russia was the largest republic in the Union of Soviet Socialist Republics (USSR).
He was Russian. Russia was the largest Republic of the Soviet Union (1922-1991).
Russia's still the largest (though by a smaller margin than when it included the entire Soviet Republic). Canada is second-largest.
Russia became first a communist state and later the largest Soviet Republic in the Soviet Union.
The USSR no longer exist; however when it did, the largest republic was Russia. At the time of the formation of of the USSR in 1923-1924, Russia was known as the Russian Soviet Federated Socialist Republic.
Chinese Soviet Republic was created in 1931.
Iran jumps to mind?
Stavropol Soviet Republic was created in 1918.
Slovak Soviet Republic was created in 1919.
Slovak Soviet Republic ended in 1919.